(Medical Xpress)—Cancer therapies have improved incrementally over the years, but cancer treatment largely remains analogous to forest fire suppression, in which the spread of fire is contained with deliberate controlled ...

Scientists at Oregon Health & Science University report that breast cancer survivors who experience pain during sexual intercourse, a common side effect of breast cancer treatment, may achieve comfort when liquid lidocaine ...

A new study points to the need for increased awareness of fertility preservation options for young patients with cancer. Published early online in Cancer, a peer-reviewed journal of the American Cancer Society, the study ...

Resveratrol and quercetin, two polyphenols that have been widely studied for their health properties, may soon become the basis of an important new advance in cancer treatment, primarily by improving the efficacy and potential ...

Advances in the treatment of adolescents and young adults with cancer have resulted in higher survival rates and longer life expectancies. But up to 20 years after people in the 20-44 age group are declared cancer-free, they ...

Children with a rare type of cancer called Wilms' tumour who are at low risk of relapsing can now be given less intensive treatment, avoiding a type of chemotherapy that can cause irreversible heart problems in later life.

Cancer survivors who smoke report fewer negative opinions about smoking, have more barriers to quitting, and are around other smokers more often than survivors who had quit before or after their diagnosis, according to a ...

Jul 02, 2015

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Cancer

Cancer (medical term: malignant neoplasm) is a class of diseases in which a group of cells display uncontrolled growth (division beyond the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes metastasis (spread to other locations in the body via lymph or blood). These three malignant properties of cancers differentiate them from benign tumors, which are self-limited, and do not invade or metastasize. Most cancers form a tumor but some, like leukemia, do not. The branch of medicine concerned with the study, diagnosis, treatment, and prevention of cancer is oncology.

Cancer may affect people at all ages, even fetuses, but the risk for most varieties increases with age. Cancer causes about 13% of all human deaths. According to the American Cancer Society, 7.6 million people died from cancer in the world during 2007. Cancers can affect all animals.

Nearly all cancers are caused by abnormalities in the genetic material of the transformed cells. These abnormalities may be due to the effects of carcinogens, such as tobacco smoke, radiation, chemicals, or infectious agents. Other cancer-promoting genetic abnormalities may be randomly acquired through errors in DNA replication, or are inherited, and thus present in all cells from birth. The heritability of cancers are usually affected by complex interactions between carcinogens and the host's genome. New aspects of the genetics of cancer pathogenesis, such as DNA methylation, and microRNAs are increasingly recognized as important.

Genetic abnormalities found in cancer typically affect two general classes of genes. Cancer-promoting oncogenes are typically activated in cancer cells, giving those cells new properties, such as hyperactive growth and division, protection against programmed cell death, loss of respect for normal tissue boundaries, and the ability to become established in diverse tissue environments. Tumor suppressor genes are then inactivated in cancer cells, resulting in the loss of normal functions in those cells, such as accurate DNA replication, control over the cell cycle, orientation and adhesion within tissues, and interaction with protective cells of the immune system.

Diagnosis usually requires the histologic examination of a tissue biopsy specimen by a pathologist, although the initial indication of malignancy can be symptoms or radiographic imaging abnormalities. Most cancers can be treated and some cured, depending on the specific type, location, and stage. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy and radiotherapy. As research develops, treatments are becoming more specific for different varieties of cancer. There has been significant progress in the development of targeted therapy drugs that act specifically on detectable molecular abnormalities in certain tumors, and which minimize damage to normal cells. The prognosis of cancer patients is most influenced by the type of cancer, as well as the stage, or extent of the disease. In addition, histologic grading and the presence of specific molecular markers can also be useful in establishing prognosis, as well as in determining individual treatments.